SOW - STUDY (80GRC023CA023).pdf

Statement of Work for (National Needs for) Transonic Dynamics Tunnel (Aeroelasticity Testing) Capabilities

The study will assess national capabilities and needs for ground test facilities (wind tunnels) used for addressing aeroelasticity issues of flight vehicles over the next 10 years. The NASA Langley Transonic Dynamics Tunnel (TDT) is a closed-circuit, continuous-flow, variable-pressure wind tunnel dedicated to identifying, understanding, and solving aeroelasticity issues confronting fixed-wing aircraft and helicopter and tiltrotor configurations. Rotary-wing tests at the TDT have investigated performance, loads, and stability characteristics, while fixed-wing buffet and divergence have been scrutinized as well. Researchers have also used the TDT to determine the effects of ground-wind loads on launch vehicles and to provide steady and unsteady aerodynamic pressure data to support computational fluid dynamics code development and validation.

Particularly useful for flutter tests is a group of four bypass valves that connect the TDT test section area to the opposite leg of the wind tunnel circuit downstream of the fan motor. In event of model instability, these quick-actuating valves open, causing a rapid reduction in the test section Mach number and dynamic pressure that serves to potentially stabilize the model. The following table illustrates the capability of TDT:

RAND’s study will consist of the following tasks, which together will enable a holistic assessment.

1. Surveying the current transonic (aeroelasticity testing) wind tunnel capabilities in the U.S.

On the supply side, the study will start by looking at current wind tunnel facilities operated by NASA and the DoD, as well as major U.S. commercial and academic facilities. It will take into account the current status of the facilities, as well as any near-to mid-term plans that may increase or reduce related capabilities and capacity. In addition, as the TDT uses a heavy gas (R-134-a) that will be more environmentally regulated, an assessment of what type of gas (air or other gas) are being used by facilities should be identified along with associated benefits and challenges. This task will be based on a thorough review of existing reports and analyses, visits to key NASA and DoD facilities, discussions with subject-matter experts, and a survey of facility operators.

2. Foresight of transonic (aeroelasticity testing) wind tunnel needs

On the demand side, the study will generate a foresight capturing potential national RDT&E activities in the transonic (aeroelasticity testing) regime over the next decade.

From these potential activities, the study will then outline the potential types of needs for transonic (aeroelasticity testing) tunnels. Historically, NASA, the DoD, and industry have trouble predicting what programs will be in existence in 5–10 years---let alone forecasting actual testing requirements for current programs beyond the next 6–12 months. Thus, the study will develop a foresight picture of the kinds of transonic (aeroelasticity testing) research and programs that might be started in the next 10 years and what kind of fundamental types of testing such activities may need. This foresight will be based on discussions with subject-matter experts within NASA, DoD and industry, existing information, plans, first principles, team-member expertise. Brief assessments about what has changed from the last RAND report will also be provided.

Due to the uncertainties involved, the results from this task will span a range of potential futures, yielding a picture of the possible rather than trying to forecast the future.

3. Assess and qualify needs for the Langley TDT

Based on the insights from the previous tasks, the study will then assess the effect of the findings from Tasks 1–2 on potential demands for the Langley TDT. Based on any readily available pricing data from NASA and the DoD, this effort will include a review of comparative costs associated with potential testing needs for the Langley TDT or satisfying those same needs in alternative capabilities. It will also lay out basic status options (ready, standby, mothball, reactivation, abandonment, or demolition) and cost based on any readily available pricing data from NASA. The study should also make a high-level assessment of the potential availability of the non-NASA facilities for NASA use and national implications to vehicle development if testing capability of remaining assets have availability issues. It will involve review of relevant materials and discussions with subject-matter experts, as well as a site visit to the Langley TDT. Cost analysis will depend on whether such pricing data are readily available and detailed cost data will not be independently verified, collected, or assessed.

4. Supporting meetings and site visits

In support of all previous tasks, members of the research team will attend selected, relevant conferences and meetings to obtain insights into current developments and in order to facilitate access to a large number of potential SMEs. NASA POC for SMEs will be provided.

5. Conclusions and final report

Finally, the study will summarize the insights gained during this effort and document our findings in a report to supporting NASA planning, decision-making, and investments.

6. Deliverables/Proposed Scheduled Payment

a. Study detailed plans for implementation (1 month from start) presented via web-ex remotely; planning document provided

b. Mid-Point Review of Study (6 month from start) presented @ NASA Langley Research Center; presentation document provided

c. Final Report and Presentation to NASA (1 year from start) presented @ NASA Langley Research Center